package com.shelpe.services.sinbad.utils;

//optionally number of images, comments and physical resolution from
//JPEG, GIF, BMP, PCX, PNG, IFF, RAS, PBM, PGM, PPM, PSD and SWF files
//(or input streams)
/*
* ImageInfo.java
*
* Version 1.5
*
* A Java class to determine image width, height and color depth for
* a number of image file formats.
*
* Written by Marco Schmidt 
* <http://www.geocities.com/marcoschmidt.geo/contact.html>.
*
* Contributed to the Public Domain.
*
* Last modification 2004-02-29
*/

/*
* Copyright 2000,2005 wingS development team.
*
* This file is part of wingS (http://wingsframework.org).
*
* wingS is free software; you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License
* as published by the Free Software Foundation; either version 2.1
* of the License, or (at your option) any later version.
*
* Please see COPYING for the complete licence.
*/

import java.io.DataInput;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import java.util.ArrayList;
import java.util.List;

/**
* Get file format, image resolution, number of bits per pixel and optionally
* number of images, comments and physical resolution from
* JPEG, GIF, BMP, PCX, PNG, IFF, RAS, PBM, PGM, PPM, PSD and SWF files
* (or input streams).
* <p/>
* Use the class like this:
* <pre>
* ImageInfo ii = new ImageInfo();
* ii.setInput(in); // in can be InputStream or RandomAccessFile
* ii.setDetermineImageNumber(true); // default is false
* ii.setCollectComments(true); // default is false
* if (!ii.check()) {
*   System.err.println("Not a supported image file format.");
*   return;
* }
* System.out.println(ii.getFormatName() + ", " + ii.getMimeType() +
*   ", " + ii.getWidth() + " x " + ii.getHeight() + " pixels, " +
*   ii.getBitsPerPixel() + " bits per pixel, " + ii.getNumberOfImages() +
*   " image(s), " + ii.getNumberOfComments() + " comment(s).");
*  // there are other properties, check out the API documentation
* </pre>
* You can also use this class as a command line program.
* Call it with a number of image file names and URLs as parameters:
* <pre>
*   java ImageInfo *.jpg *.png *.gif http://somesite.tld/image.jpg
* </pre>
* or call it without parameters and pipe data to it:
* <pre>
*   java ImageInfo &lt; image.jpg
* </pre>
* <p/>
* Known limitations:
* <ul>
* <li>When the determination of the number of images is turned off, GIF bits
* per pixel are only read from the global header.
* For some GIFs, local palettes change this to a typically larger
* value. To be certain to get the correct color depth, call
* setDetermineImageNumber(true) before calling check().
* The complete scan over the GIF file will take additional time.</li>
* <li>Transparency information is not included in the bits per pixel count.
* Actually, it was my decision not to include those bits, so it's a feature! ;-)</li>
* </ul>
* <p/>
* Requirements:
* <ul>
* <li>Java 1.1 or higher</li>
* </ul>
* <p/>
* The latest version can be found at <a href="http://www.geocities.com/marcoschmidt.geo/image-info.html">http://www.geocities.com/marcoschmidt.geo/image-info.html</a>.
* <p/>
* Written by <a href="http://www.geocities.com/marcoschmidt.geo/contact.html">Marco Schmidt</a>.
* <p/>
* This class is contributed to the Public Domain.
* Use it at your own risk.
* <p/>
* Last modification 2004-02-29.
* <p/>
* History:
* <ul>
* <li><strong>2001-08-24</strong> Initial version.</li>
* <li><strong>2001-10-13</strong> Added support for the file formats BMP and PCX.</li>
* <li><strong>2001-10-16</strong> Fixed bug in read(int[], int, int) that returned
* <li><strong>2002-01-22</strong> Added support for file formats Amiga IFF and Sun Raster (RAS).</li>
* <li><strong>2002-01-24</strong> Added support for file formats Portable Bitmap / Graymap / Pixmap (PBM, PGM, PPM) and Adobe Photoshop (PSD).
* Added new method getMimeType() to return the MIME type associated with a particular file format.</li>
* <li><strong>2002-03-15</strong> Added support to recognize number of images in file. Only works with GIF.
* Use {@link #setDetermineImageNumber} with <code>true</code> as argument to identify animated GIFs
* ({@link #getNumberOfImages()} will return a value larger than <code>1</code>).</li>
* <li><strong>2002-04-10</strong> Fixed a bug in the feature 'determine number of images in animated GIF' introduced with version 1.1.
* Thanks to Marcelo P. Lima for sending in the bug report.
* Released as 1.1.1.</li>
* <li><strong>2002-04-18</strong> Added {@link #setCollectComments(boolean)}.
* That new method lets the user specify whether textual comments are to be
* stored in an internal list when encountered in an input image file / stream.
* Added two methods to return the physical width and height of the image in dpi:
* {@link #getPhysicalWidthDpi()} and {@link #getPhysicalHeightDpi()}.
* If the physical resolution could not be retrieved, these methods return <code>-1</code>.
* </li>
* <li><strong>2002-04-23</strong> Added support for the new properties physical resolution and
* comments for some formats. Released as 1.2.</li>
* <li><strong>2002-06-17</strong> Added support for SWF, sent in by Michael Aird.
* Changed checkJpeg() so that other APP markers than APP0 will not lead to a failure anymore.
* Released as 1.3.</li>
* <li><strong>2003-07-28</strong> Bug fix - skip method now takes return values into consideration.
* Less bytes than necessary may have been skipped, leading to flaws in the retrieved information in some cases.
* Thanks to Bernard Bernstein for pointing that out.
* Released as 1.4.</li>
* <li><strong>2004-02-29</strong> Added support for recognizing progressive JPEG and
* interlaced PNG and GIF. A new method {@link #isProgressive()} returns whether ImageInfo
* has found that the storage type is progressive (or interlaced).
* Thanks to Joe Germuska for suggesting the feature.
* Bug fix: BMP physical resolution is now correctly determined.
* Released as 1.5.</li>
* </ul>
*/
public class ImageInfo {
  /**
   * Return value of {@link #getFormat()} for JPEG streams.
   * ImageInfo can extract physical resolution and comments
   * from JPEGs (only from APP0 headers).
   * Only one image can be stored in a file.
   * It is determined whether the JPEG stream is progressive
   * (see {@link #isProgressive()}).
   */
  public static final int FORMAT_JPEG = 0;

  /**
   * Return value of {@link #getFormat()} for GIF streams.
   * ImageInfo can extract comments from GIFs and count the number
   * of images (GIFs with more than one image are animations).
   * If you know of a place where GIFs store the physical resolution
   * of an image, please
   * <a href="http://www.geocities.com/marcoschmidt.geo/contact.html">send me a mail</a>!
   * It is determined whether the GIF stream is interlaced (see {@link #isProgressive()}).
   */
  public static final int FORMAT_GIF = 1;

  /**
   * Return value of {@link #getFormat()} for PNG streams.
   * PNG only supports one image per file.
   * Both physical resolution and comments can be stored with PNG,
   * but ImageInfo is currently not able to extract those.
   * It is determined whether the PNG stream is interlaced (see {@link #isProgressive()}).
   */
  public static final int FORMAT_PNG = 2;

  /**
   * Return value of {@link #getFormat()} for BMP streams.
   * BMP only supports one image per file.
   * BMP does not allow for comments.
   * The physical resolution can be stored.
   */
  public static final int FORMAT_BMP = 3;

  /**
   * Return value of {@link #getFormat()} for PCX streams.
   * PCX does not allow for comments or more than one image per file.
   * However, the physical resolution can be stored.
   */
  public static final int FORMAT_PCX = 4;

  /**
   * Return value of {@link #getFormat()} for IFF streams.
   */
  public static final int FORMAT_IFF = 5;

  /**
   * Return value of {@link #getFormat()} for RAS streams.
   * Sun Raster allows for one image per file only and is not able to
   * store physical resolution or comments.
   */
  public static final int FORMAT_RAS = 6;

  /**
   * Return value of {@link #getFormat()} for PBM streams.
   */
  public static final int FORMAT_PBM = 7;

  /**
   * Return value of {@link #getFormat()} for PGM streams.
   */
  public static final int FORMAT_PGM = 8;

  /**
   * Return value of {@link #getFormat()} for PPM streams.
   */
  public static final int FORMAT_PPM = 9;

  /**
   * Return value of {@link #getFormat()} for PSD streams.
   */
  public static final int FORMAT_PSD = 10;

  /**
   * Return value of {@link #getFormat()} for SWF (Shockwave) streams.
   */
  public static final int FORMAT_SWF = 11;

  public static final int COLOR_TYPE_UNKNOWN = -1;
  public static final int COLOR_TYPE_TRUECOLOR_RGB = 0;
  public static final int COLOR_TYPE_PALETTED = 1;
  public static final int COLOR_TYPE_GRAYSCALE = 2;
  public static final int COLOR_TYPE_BLACK_AND_WHITE = 3;

  /**
   * The names of all supported file formats.
   * The FORMAT_xyz int constants can be used as index values for
   * this array.
   */
  public static final String[] FORMAT_NAMES =
          {"jpeg", "gif", "png", "bmp", "pcx",
           "iff", "ras", "pbm", "pgm", "ppm",
           "psd", "swf"};

  /**
   * The names of the MIME types for all supported file formats.
   * The FORMAT_xyz int constants can be used as index values for
   * this array.
   */
  public static final String[] MIME_TYPE_STRINGS =
          {"image/jpeg", "image/gif", "image/png", "image/bmp", "image/pcx",
           "image/iff", "image/ras", "image/x-portable-bitmap", "image/x-portable-graymap", "image/x-portable-pixmap",
           "image/psd", "application/x-shockwave-flash"};

  private int width;
  private int height;
  private int bitsPerPixel;
  private int colorType = COLOR_TYPE_UNKNOWN;
  private boolean progressive;
  private int format;
  private InputStream in;
  private DataInput din;
  private boolean collectComments = true;
  private List comments;
  private boolean determineNumberOfImages;
  private int numberOfImages;
  private int physicalHeightDpi;
  private int physicalWidthDpi;
  private int bitBuf;
  private int bitPos;

  private void addComment(String s) {
      if (comments == null) {
          comments = new ArrayList();
      }
      comments.add(s);
  }

  /**
   * Call this method after you have provided an input stream or file
   * using {@link #setInput(java.io.InputStream)} or {@link #setInput(java.io.DataInput)}.
   * If true is returned, the file format was known and information
   * on the file's content can be retrieved using the various getXyz methods.
   *
   * @return if information could be retrieved from input
   */
  public boolean check() {
      format = -1;
      width = -1;
      height = -1;
      bitsPerPixel = -1;
      numberOfImages = 1;
      physicalHeightDpi = -1;
      physicalWidthDpi = -1;
      comments = null;
      try {
          int b1 = read() & 0xff;
          int b2 = read() & 0xff;
          if (b1 == 0x47 && b2 == 0x49) {
              return checkGif();
          } else if (b1 == 0x89 && b2 == 0x50) {
              return checkPng();
          } else if (b1 == 0xff && b2 == 0xd8) {
              return checkJpeg();
          } else if (b1 == 0x42 && b2 == 0x4d) {
              return checkBmp();
          } else if (b1 == 0x0a && b2 < 0x06) {
              return checkPcx();
          } else if (b1 == 0x46 && b2 == 0x4f) {
              return checkIff();
          } else if (b1 == 0x59 && b2 == 0xa6) {
              return checkRas();
          } else if (b1 == 0x50 && b2 >= 0x31 && b2 <= 0x36) {
              return checkPnm(b2 - '0');
          } else if (b1 == 0x38 && b2 == 0x42) {
              return checkPsd();
          } else if (b1 == 0x46 && b2 == 0x57) {
              return checkSwf();
          } else {
              return false;
          }
      } catch (IOException ioe) {
          return false;
      }
  }

  private boolean checkBmp() throws IOException {
      byte[] a = new byte[44];
      if (read(a) != a.length) {
          return false;
      }
      width = getIntLittleEndian(a, 16);
      height = getIntLittleEndian(a, 20);
      if (width < 1 || height < 1) {
          return false;
      }
      bitsPerPixel = getShortLittleEndian(a, 26);
      if (bitsPerPixel != 1 && bitsPerPixel != 4 &&
              bitsPerPixel != 8 && bitsPerPixel != 16 &&
              bitsPerPixel != 24 && bitsPerPixel != 32) {
          return false;
      }
      int x = (int) (getIntLittleEndian(a, 36) * 0.0254);
      if (x > 0) {
          setPhysicalWidthDpi(x);
      }
      int y = (int) (getIntLittleEndian(a, 40) * 0.0254);
      if (y > 0) {
          setPhysicalHeightDpi(y);
      }
      format = FORMAT_BMP;
      return true;
  }

  private boolean checkGif() throws IOException {
      final byte[] GIF_MAGIC_87A = {0x46, 0x38, 0x37, 0x61};
      final byte[] GIF_MAGIC_89A = {0x46, 0x38, 0x39, 0x61};
      byte[] a = new byte[11]; // 4 from the GIF signature + 7 from the global header
      if (read(a) != 11) {
          return false;
      }
      if ((!equals(a, 0, GIF_MAGIC_89A, 0, 4)) &&
              (!equals(a, 0, GIF_MAGIC_87A, 0, 4))) {
          return false;
      }
      format = FORMAT_GIF;
      width = getShortLittleEndian(a, 4);
      height = getShortLittleEndian(a, 6);
      int flags = a[8] & 0xff;
      bitsPerPixel = ((flags >> 4) & 0x07) + 1;
      progressive = (flags & 0x02) != 0;
      if (!determineNumberOfImages) {
          return true;
      }
      // skip global color palette
      if ((flags & 0x80) != 0) {
          int tableSize = (1 << ((flags & 7) + 1)) * 3;
          skip(tableSize);
      }
      numberOfImages = 0;
      int blockType;
      do {
          blockType = read();
          switch (blockType) {
              case (0x2c): // image separator
                  {
                      if (read(a, 0, 9) != 9) {
                          return false;
                      }
                      flags = a[8] & 0xff;
                      int localBitsPerPixel = (flags & 0x07) + 1;
                      if (localBitsPerPixel > bitsPerPixel) {
                          bitsPerPixel = localBitsPerPixel;
                      }
                      if ((flags & 0x80) != 0) {
                          skip((1 << localBitsPerPixel) * 3);
                      }
                      skip(1); // initial code length
                      int n;
                      do {
                          n = read();
                          if (n > 0) {
                              skip(n);
                          } else if (n == -1) {
                              return false;
                          }
                      } while (n > 0);
                      numberOfImages++;
                      break;
                  }
              case (0x21): // extension
                  {
                      int extensionType = read();
                      if (collectComments && extensionType == 0xfe) {
                          StringBuilder sb = new StringBuilder();
                          int n;
                          do {
                              n = read();
                              if (n == -1) {
                                  return false;
                              }
                              if (n > 0) {
                                  for (int i = 0; i < n; i++) {
                                      int ch = read();
                                      if (ch == -1) {
                                          return false;
                                      }
                                      sb.append((char) ch);
                                  }
                              }
                          } while (n > 0);
                      } else {
                          int n;
                          do {
                              n = read();
                              if (n > 0) {
                                  skip(n);
                              } else if (n == -1) {
                                  return false;
                              }
                          } while (n > 0);
                      }
                      break;
                  }
              case (0x3b): // end of file
                  {
                      break;
                  }
              default:
                  {
                      return false;
                  }
          }
      } while (blockType != 0x3b);
      return true;
  }

  private boolean checkIff() throws IOException {
      byte[] a = new byte[10];
      // read remaining 2 bytes of file id, 4 bytes file size 
      // and 4 bytes IFF subformat
      if (read(a, 0, 10) != 10) {
          return false;
      }
      final byte[] IFF_RM = {0x52, 0x4d};
      if (!equals(a, 0, IFF_RM, 0, 2)) {
          return false;
      }
      int type = getIntBigEndian(a, 6);
      if (type != 0x494c424d && // type must be ILBM...
              type != 0x50424d20) { // ...or PBM
          return false;
      }
      // loop chunks to find BMHD chunk
      do {
          if (read(a, 0, 8) != 8) {
              return false;
          }
          int chunkId = getIntBigEndian(a, 0);
          int size = getIntBigEndian(a, 4);
          if ((size & 1) == 1) {
              size++;
          }
          if (chunkId == 0x424d4844) { // BMHD chunk
              if (read(a, 0, 9) != 9) {
                  return false;
              }
              format = FORMAT_IFF;
              width = getShortBigEndian(a, 0);
              height = getShortBigEndian(a, 2);
              bitsPerPixel = a[8] & 0xff;
              return (width > 0 && height > 0 && bitsPerPixel > 0 && bitsPerPixel < 33);
          } else {
              skip(size);
          }
      } while (true);
  }

  private boolean checkJpeg() throws IOException {
      byte[] data = new byte[12];
      while (true) {
          if (read(data, 0, 4) != 4) {
              return false;
          }
          int marker = getShortBigEndian(data, 0);
          int size = getShortBigEndian(data, 2);
          if ((marker & 0xff00) != 0xff00) {
              return false; // not a valid marker
          }
          if (marker == 0xffe0) { // APPx 
              if (size < 14) {
                  return false; // APPx header must be >= 14 bytes
              }
              if (read(data, 0, 12) != 12) {
                  return false;
              }
              final byte[] APP0_ID = {0x4a, 0x46, 0x49, 0x46, 0x00};
              if (equals(APP0_ID, 0, data, 0, 5)) {
                  //System.out.println("data 7=" + data[7]);
                  if (data[7] == 1) {
                      setPhysicalWidthDpi(getShortBigEndian(data, 8));
                      setPhysicalHeightDpi(getShortBigEndian(data, 10));
                  } else if (data[7] == 2) {
                      int x = getShortBigEndian(data, 8);
                      int y = getShortBigEndian(data, 10);
                      setPhysicalWidthDpi((int) (x * 2.54f));
                      setPhysicalHeightDpi((int) (y * 2.54f));
                  }
              }
              skip(size - 14);
          } else if (collectComments && size > 2 && marker == 0xfffe) { // comment
              size -= 2;
              byte[] chars = new byte[size];
              if (read(chars, 0, size) != size) {
                  return false;
              }
              String comment = new String(chars, "iso-8859-1");
              comment = comment.trim();
              addComment(comment);
          } else if (marker >= 0xffc0 && marker <= 0xffcf && marker != 0xffc4 && marker != 0xffc8) {
              if (read(data, 0, 6) != 6) {
                  return false;
              }
              format = FORMAT_JPEG;
              bitsPerPixel = (data[0] & 0xff) * (data[5] & 0xff);
              progressive = marker == 0xffc2 || marker == 0xffc6 ||
                      marker == 0xffca || marker == 0xffce;
              width = getShortBigEndian(data, 3);
              height = getShortBigEndian(data, 1);
              return true;
          } else {
              skip(size - 2);
          }
      }
  }

  private boolean checkPcx() throws IOException {
      byte[] a = new byte[64];
      if (read(a) != a.length) {
          return false;
      }
      if (a[0] != 1) { // encoding, 1=RLE is only valid value
          return false;
      }
      // width / height
      int x1 = getShortLittleEndian(a, 2);
      int y1 = getShortLittleEndian(a, 4);
      int x2 = getShortLittleEndian(a, 6);
      int y2 = getShortLittleEndian(a, 8);
      if (x1 < 0 || x2 < x1 || y1 < 0 || y2 < y1) {
          return false;
      }
      width = x2 - x1 + 1;
      height = y2 - y1 + 1;
      // color depth
      int bits = a[1];
      int planes = a[63];
      if (planes == 1 &&
              (bits == 1 || bits == 2 || bits == 4 || bits == 8)) {
          // paletted
          bitsPerPixel = bits;
      } else if (planes == 3 && bits == 8) {
          // RGB truecolor
          bitsPerPixel = 24;
      } else {
          return false;
      }
      setPhysicalWidthDpi(getShortLittleEndian(a, 10));
      setPhysicalHeightDpi(getShortLittleEndian(a, 10));
      format = FORMAT_PCX;
      return true;
  }

  private boolean checkPng() throws IOException {
      final byte[] PNG_MAGIC = {0x4e, 0x47, 0x0d, 0x0a, 0x1a, 0x0a};
      byte[] a = new byte[27];
      if (read(a) != 27) {
          return false;
      }
      if (!equals(a, 0, PNG_MAGIC, 0, 6)) {
          return false;
      }
      format = FORMAT_PNG;
      width = getIntBigEndian(a, 14);
      height = getIntBigEndian(a, 18);
      bitsPerPixel = a[22] & 0xff;
      colorType = a[23] & 0xff;
      if (colorType == 2 || colorType == 6) {
          bitsPerPixel *= 3;
      }
      progressive = (a[26] & 0xff) != 0;
      return true;
  }

  private boolean checkPnm(int id) throws IOException {
      if (id < 1 || id > 6) {
          return false;
      }
      final int[] PNM_FORMATS = {FORMAT_PBM, FORMAT_PGM, FORMAT_PPM};
      format = PNM_FORMATS[(id - 1) % 3];
      boolean hasPixelResolution = false;
      String s;
      while (true) {
          s = readLine();
          if (s != null) {
              s = s.trim();
          }
          if (s == null || s.length() < 1) {
              continue;
          }
          if (s.charAt(0) == '#') { // comment
              if (collectComments && s.length() > 1) {
                  addComment(s.substring(1));
              }
              continue;
          }
          if (!hasPixelResolution) { // split "343 966" into width=343, height=966
              int spaceIndex = s.indexOf(' ');
              if (spaceIndex == -1) {
                  return false;
              }
              String widthString = s.substring(0, spaceIndex);
              spaceIndex = s.lastIndexOf(' ');
              if (spaceIndex == -1) {
                  return false;
              }
              String heightString = s.substring(spaceIndex + 1);
              try {
                  width = Integer.parseInt(widthString);
                  height = Integer.parseInt(heightString);
              } catch (NumberFormatException nfe) {
                  return false;
              }
              if (width < 1 || height < 1) {
                  return false;
              }
              if (format == FORMAT_PBM) {
                  bitsPerPixel = 1;
                  return true;
              }
              hasPixelResolution = true;
          } else {
              int maxSample;
              try {
                  maxSample = Integer.parseInt(s);
              } catch (NumberFormatException nfe) {
                  return false;
              }
              if (maxSample < 0) {
                  return false;
              }
              for (int i = 0; i < 25; i++) {
                  if (maxSample < (1 << (i + 1))) {
                      bitsPerPixel = i + 1;
                      if (format == FORMAT_PPM) {
                          bitsPerPixel *= 3;
                      }
                      return true;
                  }
              }
              return false;
          }
      }
  }

  private boolean checkPsd() throws IOException {
      byte[] a = new byte[24];
      if (read(a) != a.length) {
          return false;
      }
      final byte[] PSD_MAGIC = {0x50, 0x53};
      if (!equals(a, 0, PSD_MAGIC, 0, 2)) {
          return false;
      }
      format = FORMAT_PSD;
      width = getIntBigEndian(a, 16);
      height = getIntBigEndian(a, 12);
      int channels = getShortBigEndian(a, 10);
      int depth = getShortBigEndian(a, 20);
      bitsPerPixel = channels * depth;
      return (width > 0 && height > 0 && bitsPerPixel > 0 && bitsPerPixel <= 64);
  }

  private boolean checkRas() throws IOException {
      byte[] a = new byte[14];
      if (read(a) != a.length) {
          return false;
      }
      final byte[] RAS_MAGIC = {0x6a, (byte) 0x95};
      if (!equals(a, 0, RAS_MAGIC, 0, 2)) {
          return false;
      }
      format = FORMAT_RAS;
      width = getIntBigEndian(a, 2);
      height = getIntBigEndian(a, 6);
      bitsPerPixel = getIntBigEndian(a, 10);
      return (width > 0 && height > 0 && bitsPerPixel > 0 && bitsPerPixel <= 24);
  }

  // Written by Michael Aird.
  private boolean checkSwf() throws IOException {
      //get rid of the last byte of the signature, the byte of the version and 4 bytes of the size
      byte[] a = new byte[6];
      if (read(a) != a.length) {
          return false;
      }
      format = FORMAT_SWF;
      int bitSize = (int) readUBits(5);
      int minX = readSBits(bitSize);
      int maxX = readSBits(bitSize);
      int minY = readSBits(bitSize);
      int maxY = readSBits(bitSize);
      width = maxX / 20; //cause we're in twips
      height = maxY / 20;  //cause we're in twips
      setPhysicalWidthDpi(72);
      setPhysicalHeightDpi(72);
      return (width > 0 && height > 0);
  }

  /**
   * Run over String list, return false iff at least one of the arguments
   * equals <code>-c</code>.
   */
  private static boolean determineVerbosity(String[] args) {
      if (args != null && args.length > 0) {
          for (int i = 0; i < args.length; i++) {
              if ("-c".equals(args[i])) {
                  return false;
              }
          }
      }
      return true;
  }

  private boolean equals(byte[] a1, int offs1, byte[] a2, int offs2, int num) {
      while (num-- > 0) {
          if (a1[offs1++] != a2[offs2++]) {
              return false;
          }
      }
      return true;
  }

  /**
   * If {@link #check()} was successful, returns the image's number of bits per pixel.
   * Does not include transparency information like the alpha channel.
   *
   * @return number of bits per image pixel
   */
  public int getBitsPerPixel() {
      return bitsPerPixel;
  }

  /**
   * Returns the index'th comment retrieved from the image.
   *
   * @throws java.lang.IllegalArgumentException
   *          if index is smaller than 0 or larger than or equal
   *          to the number of comments retrieved
   * @see #getNumberOfComments
   */
  public String getComment(int index) {
      if (comments == null || index < 0 || index >= comments.size()) {
          throw new IllegalArgumentException("Not a valid comment index: " + index);
      }
      return (String) comments.get(index);
  }

  /**
   * If {@link #check()} was successful, returns the image format as one
   * of the FORMAT_xyz constants from this class.
   * Use {@link #getFormatName()} to get a textual description of the file format.
   *
   * @return file format as a FORMAT_xyz constant
   */
  public int getFormat() {
      return format;
  }

  /**
   * If {@link #check()} was successful, returns the image format's name.
   * Use {@link #getFormat()} to get a unique number.
   *
   * @return file format name
   */
  public String getFormatName() {
      if (format >= 0 && format < FORMAT_NAMES.length) {
          return FORMAT_NAMES[format];
      } else {
          return "?";
      }
  }

  /**
   * If {@link #check()} was successful, returns one the image's vertical
   * resolution in pixels.
   *
   * @return image height in pixels
   */
  public int getHeight() {
      return height;
  }

  private int getIntBigEndian(byte[] a, int offs) {
      return
              (a[offs] & 0xff) << 24 |
              (a[offs + 1] & 0xff) << 16 |
              (a[offs + 2] & 0xff) << 8 |
              a[offs + 3] & 0xff;
  }

  private int getIntLittleEndian(byte[] a, int offs) {
      return
              (a[offs + 3] & 0xff) << 24 |
              (a[offs + 2] & 0xff) << 16 |
              (a[offs + 1] & 0xff) << 8 |
              a[offs] & 0xff;
  }

  /**
   * If {@link #check()} was successful, returns a String with the
   * MIME type of the format.
   *
   * @return MIME type, e.g. <code>image/jpeg</code>
   */
  public String getMimeType() {
      if (format >= 0 && format < MIME_TYPE_STRINGS.length) {
          if (format == FORMAT_JPEG && progressive) {
              return "image/pjpeg";
          }
          return MIME_TYPE_STRINGS[format];
      } else {
          return null;
      }
  }

  /**
   * If {@link #check()} was successful and {@link #setCollectComments(boolean)} was called with
   * <code>true</code> as argument, returns the number of comments retrieved
   * from the input image stream / file.
   * Any number &gt;= 0 and smaller than this number of comments is then a
   * valid argument for the {@link #getComment(int)} method.
   *
   * @return number of comments retrieved from input image
   */
  public int getNumberOfComments() {
      if (comments == null) {
          return 0;
      } else {
          return comments.size();
      }
  }

  /**
   * Returns the number of images in the examined file.
   * Assumes that <code>setDetermineImageNumber(true);</code> was called before
   * a successful call to {@link #check()}.
   * This value can currently be only different from <code>1</code> for GIF images.
   *
   * @return number of images in file
   */
  public int getNumberOfImages() {
      return numberOfImages;
  }

  /**
   * Returns the physical height of this image in dots per inch (dpi).
   * Assumes that {@link #check()} was successful.
   * Returns <code>-1</code> on failure.
   *
   * @return physical height (in dpi)
   * @see #getPhysicalWidthDpi()
   * @see #getPhysicalHeightInch()
   */
  public int getPhysicalHeightDpi() {
      return physicalHeightDpi;
  }

  /**
   * If {@link #check()} was successful, returns the physical width of this image in dpi (dots per inch)
   * or -1 if no value could be found.
   *
   * @return physical height (in dpi)
   * @see #getPhysicalHeightDpi()
   * @see #getPhysicalWidthDpi()
   * @see #getPhysicalWidthInch()
   */
  public float getPhysicalHeightInch() {
      int h = getHeight();
      int ph = getPhysicalHeightDpi();
      if (h > 0 && ph > 0) {
          return ((float) h) / ((float) ph);
      } else {
          return -1.0f;
      }
  }

  /**
   * If {@link #check()} was successful, returns the physical width of this image in dpi (dots per inch)
   * or -1 if no value could be found.
   *
   * @return physical width (in dpi)
   * @see #getPhysicalHeightDpi()
   * @see #getPhysicalWidthInch()
   * @see #getPhysicalHeightInch()
   */
  public int getPhysicalWidthDpi() {
      return physicalWidthDpi;
  }

  /**
   * Returns the physical width of an image in inches, or
   * <code>-1.0f</code> if width information is not available.
   * Assumes that {@link #check} has been called successfully.
   *
   * @return physical width in inches or <code>-1.0f</code> on failure
   * @see #getPhysicalWidthDpi
   * @see #getPhysicalHeightInch
   */
  public float getPhysicalWidthInch() {
      int w = getWidth();
      int pw = getPhysicalWidthDpi();
      if (w > 0 && pw > 0) {
          return ((float) w) / ((float) pw);
      } else {
          return -1.0f;
      }
  }

  private int getShortBigEndian(byte[] a, int offs) {
      return
              (a[offs] & 0xff) << 8 |
              (a[offs + 1] & 0xff);
  }

  private int getShortLittleEndian(byte[] a, int offs) {
      return (a[offs] & 0xff) | (a[offs + 1] & 0xff) << 8;
  }

  /**
   * If {@link #check()} was successful, returns one the image's horizontal
   * resolution in pixels.
   *
   * @return image width in pixels
   */
  public int getWidth() {
      return width;
  }

  /**
   * Returns whether the image is stored in a progressive (also called: interlaced) way.
   *
   * @return true for progressive/interlaced, false otherwise
   */
  public boolean isProgressive() {
      return progressive;
  }

  private static void print(String sourceName, ImageInfo ii, boolean verbose) {
      if (verbose) {
          printVerbose(sourceName, ii);
      } else {
          printCompact(sourceName, ii);
      }
  }

  private static void printCompact(String sourceName, ImageInfo imageInfo) {
      System.out.println(imageInfo.getFormatName() + ";" +
              imageInfo.getMimeType() + ";" +
              imageInfo.getWidth() + ";" +
              imageInfo.getHeight() + ";" +
              imageInfo.getBitsPerPixel() + ";" +
              imageInfo.getNumberOfImages() + ";" +
              imageInfo.getPhysicalWidthDpi() + ";" +
              imageInfo.getPhysicalHeightDpi() + ";" +
              imageInfo.getPhysicalWidthInch() + ";" +
              imageInfo.getPhysicalHeightInch() + ";" +
              imageInfo.isProgressive());
  }

  private static void printLine(int indentLevels, String text, float value, float minValidValue) {
      if (value < minValidValue) {
          return;
      }
      printLine(indentLevels, text, Float.toString(value));
  }

  private static void printLine(int indentLevels, String text, int value, int minValidValue) {
      if (value >= minValidValue) {
          printLine(indentLevels, text, Integer.toString(value));
      }
  }

  private static void printLine(int indentLevels, String text, String value) {
      if (value == null || value.length() == 0) {
          return;
      }
      while (indentLevels-- > 0) {
          System.out.print("\t");
      }
      if (text != null && text.length() > 0) {
          System.out.print(text);
          System.out.print(" ");
      }
      System.out.println(value);
  }

  private static void printVerbose(String sourceName, ImageInfo ii) {
      printLine(0, null, sourceName);
      printLine(1, "File format: ", ii.getFormatName());
      printLine(1, "MIME type: ", ii.getMimeType());
      printLine(1, "Width (pixels): ", ii.getWidth(), 1);
      printLine(1, "Height (pixels): ", ii.getHeight(), 1);
      printLine(1, "Bits per pixel: ", ii.getBitsPerPixel(), 1);
      printLine(1, "Progressive: ", Boolean.toString(ii.isProgressive()));
      printLine(1, "Number of images: ", ii.getNumberOfImages(), 1);
      printLine(1, "Physical width (dpi): ", ii.getPhysicalWidthDpi(), 1);
      printLine(1, "Physical height (dpi): ", ii.getPhysicalHeightDpi(), 1);
      printLine(1, "Physical width (inches): ", ii.getPhysicalWidthInch(), 1.0f);
      printLine(1, "Physical height (inches): ", ii.getPhysicalHeightInch(), 1.0f);
      int numComments = ii.getNumberOfComments();
      printLine(1, "Number of textual comments: ", numComments, 1);
      if (numComments > 0) {
          for (int i = 0; i < numComments; i++) {
              printLine(2, null, ii.getComment(i));
          }
      }
  }

  private int read() throws IOException {
      if (in != null) {
          return in.read();
      } else {
          return din.readByte();
      }
  }

  private int read(byte[] a) throws IOException {
      if (in != null) {
          return in.read(a);
      } else {
          din.readFully(a);
          return a.length;
      }
  }

  private int read(byte[] a, int offset, int num) throws IOException {
      if (in != null) {
          return in.read(a, offset, num);
      } else {
          din.readFully(a, offset, num);
          return num;
      }
  }

  private String readLine() throws IOException {
      return readLine(new StringBuilder());
  }

  private String readLine(StringBuilder sb) throws IOException {
      boolean finished;
      do {
          int value = read();
          finished = (value == -1 || value == 10);
          if (!finished) {
              sb.append((char) value);
          }
      } while (!finished);
      return sb.toString();
  }

  private long readUBits(int numBits) throws IOException {
      if (numBits == 0) {
          return 0;
      }
      int bitsLeft = numBits;
      long result = 0;
      if (bitPos == 0) { //no value in the buffer - read a byte
          if (in != null) {
              bitBuf = in.read();
          } else {
              bitBuf = din.readByte();
          }
          bitPos = 8;
      }

      while (true) {
          int shift = bitsLeft - bitPos;
          if (shift > 0) {
              // Consume the entire buffer
              result |= bitBuf << shift;
              bitsLeft -= bitPos;

              // Get the next byte from the input stream
              if (in != null) {
                  bitBuf = in.read();
              } else {
                  bitBuf = din.readByte();
              }
              bitPos = 8;
          } else {
              // Consume a portion of the buffer
              result |= bitBuf >> -shift;
              bitPos -= bitsLeft;
              bitBuf &= 0xff >> (8 - bitPos); // mask off the consumed bits

              return result;
          }
      }
  }

  /**
   * Read a signed value from the given number of bits
   */
  private int readSBits(int numBits) throws IOException {
      // Get the number as an unsigned value.
      long uBits = readUBits(numBits);

      // Is the number negative?
      if ((uBits & (1L << (numBits - 1))) != 0) {
          // Yes. Extend the sign.
          uBits |= -1L << numBits;
      }

      return (int) uBits;
  }

  private void synchBits() {
      bitBuf = 0;
      bitPos = 0;
  }

  private String readLine(int firstChar) throws IOException {
      StringBuilder result = new StringBuilder();
      result.append((char) firstChar);
      return readLine(result);
  }

  private static void run(String sourceName, InputStream in, ImageInfo imageInfo, boolean verbose) {
      imageInfo.setInput(in);
      imageInfo.setDetermineImageNumber(false);
      imageInfo.setCollectComments(verbose);
      if (imageInfo.check()) {
          print(sourceName, imageInfo, verbose);
      }
  }

  /**
   * Specify whether textual comments are supposed to be extracted from input.
   * Default is <code>false</code>.
   * If enabled, comments will be added to an internal list.
   *
   * @param newValue if <code>true</code>, this class will read comments
   * @see #getNumberOfComments
   * @see #getComment
   */
  public void setCollectComments(boolean newValue) {
      collectComments = newValue;
  }

  /**
   * Specify whether the number of images in a file is to be
   * determined - default is <code>false</code>.
   * This is a special option because some file formats require running over
   * the entire file to find out the number of images, a rather time-consuming
   * task.
   * Not all file formats support more than one image.
   * If this method is called with <code>true</code> as argument,
   * the actual number of images can be queried via
   * {@link #getNumberOfImages()} after a successful call to
   * {@link #check()}.
   *
   * @param newValue will the number of images be determined?
   * @see #getNumberOfImages
   */
  public void setDetermineImageNumber(boolean newValue) {
      determineNumberOfImages = newValue;
  }

  /**
   * Set the input stream to the argument stream (or file).
   * Note that {@link java.io.RandomAccessFile} implements
   * {@link java.io.DataInput}.
   *
   * @param dataInput the input stream to read from
   */
  public void setInput(DataInput dataInput) {
      din = dataInput;
      in = null;
  }

  /**
   * Set the input stream to the argument stream (or file).
   *
   * @param inputStream the input stream to read from
   */
  public void setInput(InputStream inputStream) {
      in = inputStream;
      din = null;
  }

  private void setPhysicalHeightDpi(int newValue) {
      physicalWidthDpi = newValue;
  }

  private void setPhysicalWidthDpi(int newValue) {
      physicalHeightDpi = newValue;
  }

  private void skip(int num) throws IOException {
      while (num > 0) {
          long result;
          if (in != null) {
              result = in.skip(num);
          } else {
              result = din.skipBytes(num);
          }
          if (result > 0) {
              num -= result;
          }
      }
  }
}

